Prosecutors said Chad Chritton and Melinda Drabek-Chritton denied the 15-year-old girl food and forced her to live in the basement. Prosecutors have also accused the girl's stepbrother of sexually assaulting her.

The husband and wife are scheduled to enter pleas Monday afternoon to charges of reckless endangerment, child abuse and child neglect.

The stepbrother is scheduled to enter pleas to a child abuse charge and two sexual assault counts at the same proceeding.

The defense is arguing that the young girl was mentally ill and tried to harm herself.

Stay tuned to WISC-TV and Channel 3000 for continuing coverage.

Copyright 2012 by Channel 3000. The Associated Press contributed to this report. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.